8

我正在尝试编译以下测试程序：

#include <GL/glfw.h>

int main(int argc, char** argv) {
    if(!glfwInit()) {
        return -1;
    }

    if(!glfwOpenWindow(640, 480, 8, 8, 8, 0, 24, 0, GLFW_WINDOW)) {
        return -1;
    }

    while(glfwGetWindowParam(GLFW_OPENED)) {
        glfwSwapBuffers();
    }

    return 0;
}

但我总是undefined reference在 GLFW 功能方面遇到错误。

下面是我的makefile：

CXX = clang++
CXXFLAGS = -Wall -std=c++0x
LDFLAGS = -lglfw

OBJ_DIR = bin
LIB_DIR = -L/usr/lib
INC_DIR = -I/usr/include

SOURCE = main.cpp
OBJECTS = ${SOURCE:%.cpp=$(OBJ_DIR)/%.o}
EXECUTABLE = hello

all: init $(OBJECTS) $(EXECUTABLE)

$(EXECUTABLE):
    $(CXX) $(CXXFLAGS) $(LDFLAGS) $(LIB_DIR) -o $@ $(OBJECTS)

$(OBJ_DIR)/%.o: %.cpp
    $(CXX) $(INC_DIR) -c $< -o $@

init:
    @mkdir -p "$(OBJ_DIR)"

clean:
    @rm -rf $(OBJ_DIR) $(EXECUTABLE)

我肯定有glfw.h，libglfw.a/.so当我跑步时，locate glfw我得到：

:~$ locate glfw
/usr/include/GL/glfw.h
/usr/lib/libglfw.a
/usr/lib/libglfw.so
/usr/lib/libglfw.so.2
/usr/lib/libglfw.so.2.6

的输出nm /usr/lib/libglfw.a | grep glfwInit：

:~$ nm /usr/lib/libglfw.a | grep glfwInit
                 U _glfwInitialized
                 U _glfwInitialized
                 U _glfwInitialized
                 U _glfwInitialized
0000000000000000 B _glfwInitialized
0000000000000000 T glfwInit
                 U _glfwInitialized
                 U _glfwInitialized
                 U _glfwInitialized
                 U _glfwInitialized
                 U _glfwInitialized
                 U _glfwInitJoysticks
                 U _glfwInitTimer
00000000000000c0 T _glfwInitJoysticks
0000000000000000 T _glfwInitTimer

以及来自 clang 的详细信息：

clang++ -I/usr/include -c main.cpp -o bin/main.o
clang++ -Wall -std=c++0x -Wl --verbose -lglfw -lGL -lGLU -L/usr/lib -o hello bin/main.o
Ubuntu clang version 3.0-6ubuntu3 (tags/RELEASE_30/final) (based on LLVM 3.0)
Target: x86_64-pc-linux-gnu
Thread model: posix
clang: warning: argument unused during compilation: '-std=c++0x'
 "/usr/bin/ld" -z relro --hash-style=gnu --as-needed --build-id --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o hello /usr/lib/gcc/x86_64-linux-gnu/4.6/../../../x86_64-linux-gnu/crt1.o /usr/lib/gcc/x86_64-linux-gnu/4.6/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/4.6/crtbegin.o -L/usr/lib -L/usr/lib/gcc/x86_64-linux-gnu/4.6 -L/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../x86_64-linux-gnu -L/lib/x86_64-linux-gnu -L/lib/../lib64 -L/usr/lib/x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/4.6/../../.. -L/lib/x86_64-linux-gnu -L/lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib -lglfw -lGL -lGLU bin/main.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/lib/gcc/x86_64-linux-gnu/4.6/crtend.o /usr/lib/gcc/x86_64-linux-gnu/4.6/../../../x86_64-linux-gnu/crtn.o
bin/main.o: In function `main':
main.cpp:(.text+0x17): undefined reference to `glfwInit'
main.cpp:(.text+0x76): undefined reference to `glfwOpenWindow'
main.cpp:(.text+0x97): undefined reference to `glfwGetWindowParam'
main.cpp:(.text+0xa7): undefined reference to `glfwSwapBuffers'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [hello] Error 1

好像找不到图书馆？

4

1 回答 1

12

问题是glfw库在依赖于它们的目标文件之前被指定给链接器。ld搜索库以仅针对它在其正在处理的文件列表中所知道的依赖关系解析依赖关系。因此，在ld搜索libglfw.a时它还不知道glfwInit依赖关系main.o。ld（默认情况下）不会再次搜索库。

尝试：

$(EXECUTABLE):
    $(CXX) $(CXXFLAGS) $(LIB_DIR) -o $@ $(OBJECTS)  $(LDFLAGS)

此外，库可能应该在LDLIBS（或LIBS）变量中指定 -LDFLAGS通常用于链接器选项：

CXX = clang++
CXXFLAGS = -Wall -std=c++0x
LDLIBS = -lglfw -lGL -lGLU

OBJ_DIR = bin
LIB_DIR = -L/usr/lib
INC_DIR = -I/usr/include

SOURCE = main.cpp
OBJECTS = ${SOURCE:%.cpp=$(OBJ_DIR)/%.o}
EXECUTABLE = hello

all: init $(OBJECTS) $(EXECUTABLE)

$(EXECUTABLE):
    $(CXX) $(LDFLAGS) $(LIB_DIR) -o $@ $(OBJECTS) $(LDLIBS)

$(OBJ_DIR)/%.o: %.cpp
    $(CXX) $(INC_DIR) -c $< -o $@

init:
    @mkdir -p "$(OBJ_DIR)"

clean:
    @rm -rf $(OBJ_DIR) $(EXECUTABLE)
于 2013-05-12T17:46:08.033 回答